Painutamisel

Painutamisel is the Estonian term for bending, a metalforming process in which a straight workpiece is deformed into an angle or curvature. It is widely used for sheet metal, tubes, and bars and is performed with tools such as punches and dies, rollers, or bending presses to achieve the desired geometry.

The process relies on plastic deformation: the material yields and remains permanently bent after the forming force is removed. The final shape depends on material properties (ductility, yield strength, work hardening), thickness, bend radius (R) and angle, and lubrication. The R to thickness (R/t) ratio is a key design parameter: a small radius can cause cracking or tearing, while a large radius may affect fit and stiffness. Process parameters such as clamping force, forming speed, and lubrication influence tool wear and surface quality.

Bending methods include forming with a die and punch, roll bending for curved profiles, and tube bending for pipes and tubes. Equipment ranges from simple bending brakes to specialized rollforming and continuous bending systems. Quality control focuses on achieving the required tolerances, surface finish, and structural integrity, while managing springback—elastic recovery after unloading—which often requires compensation in tooling or process planning.

Common defects in painutamisel include wrinkling, cracking, springback, and surface imperfections. Proper material selection, accurate radius design, appropriate lubrication, and tool history management help mitigate these issues.

Applications span many industries, including automotive, construction, appliance manufacturing, and consumer electronics enclosures, where precise curved components and lightweight yet strong parts are required. See also metal forming, sheet metal bending, and tube bending.